1. Fear discrimination is restricted to the Te1–PL cortex pathway.
Fear discrimination is restricted to the Te1–PL cortex pathway. A, Schematic representation of the AAV5:CaMKIIα:eNpHR3.0-mCherry injection in the Te3 and optic fiber implant in the PL cortex region (left); spreading of the virus into the Te3 and Te3 axon terminals into the PL cortex, as revealed by mCherry immunostaining and relative fiber tracks (right). Scale bars: larger image, 500 μm; smaller image, 25 μm. B, Discriminator animals showed a low rate of freezing to the new 15 kHz tone alone and to the 15 kHz tone delivered with the light on, while freezing to CS was significantly more likely with respect to the previous conditions. No differences were evident between the new 15 kHz tone and 15 kHz tone + light-on. C, Generalizer animals showed an increase in the freezing response during presentation of the new 15 kHz tone, the 15 kHz tone delivered with the light on, and CS. D, Schematic representation of the AAV5:CaMKIIα:eNpHR3.0-mCherry injection in the Te1 and optic fiber implant in the BLA region (left). Colocalization of mCherry and the synaptic protein bassoon at Te1 axon terminals into the BLA (right). Scale bar, 25 μm. E, Representative histology of optic fibers tracks in the BLA with relative Nissl staining. Scale bar, 500 μm. F, eNpHR3.0-mCherry and mCherry discriminators did not differ in all conditions, both exhibiting only an increase in the freezing response to the CS. G, No effects were observed in the generalizers. **p < All data are mean ± SEM.
Giulia Concina et al. J. Neurosci. 2018;38:
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